1. Field of the Disclosure
The present disclosure relates generally to supply items used in electrophotographic image forming devices and more particularly to a retainer for containing processing circuitry mountable on a supply item in an imaging forming device and having positional control features.
2. Description of the Related Art
In order to reduce the premature replacement of components used in an image forming device, toner cartridge manufacturers have begun to separate components having a longer life from those having a shorter life into separate replaceable units. Relatively longer life components such as a developer roll, a toner adder roll, a doctor blade and a photoconductive drum are positioned in one replaceable supply item commonly referred to as an imaging unit. The image forming device's toner supply, which is consumed relatively quickly in comparison with the components housed in the imaging unit, is provided in a reservoir in a separate replaceable supply item in the form of a toner cartridge that mates with the imaging unit. In this configuration, the number of components housed in the toner cartridge is reduced in comparison with traditional toner cartridges.
Onboard such supply items, there is processing circuitry used to store information about the supply item such as life, printing variables, etc. The processing circuitry is mounted on a circuit board on the supply item such that the contacts on the circuit board mate with corresponding contacts in the image forming device when the supply item is installed in the image forming device. In order for the image forming device to communicate with the processing circuitry, electrical connection must be made between the processing circuitry on the supply item and the image forming device. As such, it is important to accurately position the circuit board on the supply item relative to the connector contacts in the image forming device. This can be challenging in that circuit boards for this processing circuitry may have dimensional variation and few locating features. Also, the tolerances in the image forming device frame dimensions can lead to the connector contacts of the image forming device and the circuit board of supply item's processing circuitry not being properly positioned relative to each other. Further, to establish a reliable electrical connection, the contacts of the image forming device connector need to exert force on the supply item's processing circuitry circuit board. However, the force balance between the toner cartridge and the imaging unit is delicate because an imbalance of forces can cause print defects. Furthermore, these supply items can see many installations into a printer throughout their lives during which contaminants such as toner, paper dust, etc., can settle in the terminals of the circuit board of the supply item's processing device. These contaminants act like sandpaper when sandwiched between the image forming device's connecting pins and the contacts or terminals on processing circuitry circuit board which cause the contacting surfaces of the pins and the terminals to become worn and, in some cases, leads to a malfunction of the processing circuitry.
Accordingly, it will be appreciated that a retainer having positional control features that permit precise alignment for establishing a reliable electrical connection between the supply items's processing circuitry and the image forming device while minimizing external forces on the supply item and permitting the removal of contaminants from the contact surface of the processing circuitry circuit board is desired.